mass scaling problem

[rw5]

hi,
I'm modeling a cyclic loaded masonry wall in abaqus explicit.
Since the model is relatively large, I've tried to use mass scaling to slightly adjust the stable time increment and reduce the computation time.
I have an initial step + 4 additional steps, and I've assigned mass scaling in the first step. Other steps use the mass scaling definition from the first step.
However, when I run the calculation, the stable time increment in the job monitor table is the same as before. For some reason mass scaling wasn't applied.
I've tried applying mass scaling on the whole model and on the individual set, however, the result was the same.

Any idea on what the problem could be?

tnx

 

[FEA way]

Check the warning messages - are there any related to mass scaling ? Try scaling (the whole model) by factor.

 

[rw5]

There aren't any warning messages related to mass scaling.
I've tried scaling the whole model by a factor (100) and the stable time incr is now 2,72e-06.
But I'm not sure whether applying the mass scaling on all elements is suitable for my model since I only wanted to apply it to finite elements belonging to masonry retrofitting elements(mortar and glass fibers) which are smaller because their smaller thickness.

 

[FEA way]

When you apply it only to a selected region, there can still be some elements with lower stable time increment somewhere else. You can use the Verify Mesh tool in the Mesh module to check which elements have low stable time increment.

 

[rw5]

Yeah, I've used the verify mesh tool to create a set containing the elements with low stable time (PoorElements-set in the Edit Mass Scaling dialog window - see snip above).

 

[FEA way]

Ok but what if you apply mass scaling defined with a target time increment to the whole model ? Does Abaqus use that value or still show the smaller one ?

 

[rw5]

It still shows the smaller one.

Only scaling the whole model by a factor works.